The present invention relates to a fuse with a separating element, in particular to a melting fuse for a vehicle battery.
In high-voltage vehicle batteries, high-voltage contactors are conventionally employed at the external vehicle terminals for the purpose of cutting out excess currents (up to about 1000-2000 A). For higher currents, fuses are built in, because contactors are no longer able to isolate such currents. Located in these fuses, depending on the type, is a fusible element (frequently made of copper) with cross-sectionally constricted portions. These cross-sectionally constricted portions or constrictions melt in the event of short-circuit currents. The higher the current or voltage, the longer an arc is able to remain in existence until it dies out. Fuses with several constrictions are therefore used for high voltages (currently about 450 V) and currents (currently about 8 kA). In this way, at each constriction a clearance arises which in total has to be overcome by individual arcs. The length of the fuse is consequently determined by the maximum voltage and the maximum current. Fuses are conventionally filled with sand, which is responsible for the arc dying out as quickly as possible.
Such a fuse according to the state of the art is shown in FIG. 3. Said fuse includes a fusible element 11 with several constrictions 12 at which the conductive cross section of the fusible element 11 has been reduced. The two ends 13 and 14 of the fusible element 11 are suitable to integrate the fuse 10 into an electric circuit. At least the constrictions 12 are surrounded by a fuse housing 15. In the case of a short circuit in the electric circuit into which the fuse has been integrated, a high current flows across the fusible element 11. The latter begins to melt and, as a result, is firstly interrupted at one of the constrictions 12. By virtue of the voltage applied to the fuse 10, an arc may occur between the interrupted portions of the fusible element 11. By virtue of the current consequently continuing to flow through the fusible element 11, the latter is also interrupted at the further constrictions 12 by melting of the fusible element 11. This process continues until at least so many constrictions 12 of the fusible element 11 have fused that the distance to be bridged by arcs within the fuse 10 is so great that a breaking of the arcs occurs. Since the maximum length of the distance to be bridged by arcs is dependent on the number of constrictions 12 of the fusible element 11, it is necessary to form such a fuse 10 according to the state of the art to be appropriately long.
A fuse according to the state of the art is presented in JPH11329206A. Described in the latter is a fuse in which a path to be bridged by an arc in the case of a tripped fuse is lengthened by means of a magnetic field generated by two magnets.
A further fuse according to the state of the art is presented in US2009315664A. A rapid interruption of a current is obtained in the fuse presented in this document by virtue of the fact that a fusible element is pressed between insulating separating plates by an induced magnetic field.
A further fuse according to the state of the art is presented in WO12123589A. In the latter, a fuse and a process for producing a fuse are described. The fuse includes means for influencing an electromagnetic field of a fusible element.
A fuse base according to the state of the art is presented in KR20040013718A. The fuse base that is described includes two magnets. The magnetic field caused by these magnets has been configured to prevent an appearance of arcs when inserting or taking out a fuse.
Since batteries with such fuses are employed especially in the automotive field, a design of the fuse is desirable that is as compact as possible.